Electronic structure of and quantum size effect in III-V and II-VI semiconducting nanocrystals using a realistic tight binding approach

Viswanatha, Ranjani and Sapra, Sameer and Saha-Dasgupta, Tanusri and Sarma, DD (2005) Electronic structure of and quantum size effect in III-V and II-VI semiconducting nanocrystals using a realistic tight binding approach. In: Physical Review B, 72 (4).

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Abstract

We analyze the electronic structure of group III-V semiconductors obtained within full potential linearized augmented plane wave(FP-LAPW) method and arrive at a realistic and minimal tight-binding model, parametrized to provide an accurate description of both valence and conduction bands. It is shown that the cation $sp^{3}$ -anion $sp^{3}d^{5}$ basis along with the next nearest neighbor model for hopping interactions is sufficient to describe the electronic structure of these systems over a wide energy range, obviating the use of any fictitious $s^{*}$ orbital, employed previously. Similar analyses were also performed for the II-VI semiconductors, using the more accurate FP-LAPW method compared to previous approaches, in order to enhance reliability of the parameter values. Using these parameters, we calculate the electronic structure of III-V and II-VI nanocrystals in real space with sizes ranging up to about 7 nm in diameter,establishing a quantitatively accurate description of the bandgap variation with sizes for the various nanocrystals by comparing with available experimental results from the literature.

Item Type:	Journal Article
Publication:	Physical Review B
Publisher:	American Physical Society
Additional Information:	Copyright for this article belongs to American Physical Society.
Keywords:	optical-properties;gan nanoparticles;gallium-arsenide;dots; inp;confinement;crystallites;spectroscopy;emission;systems
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	25 Aug 2005
Last Modified:	19 Sep 2010 04:19
URI:	http://eprints.iisc.ac.in/id/eprint/3562

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